System and method for analyzing and imaging and enhanced three-dimensional volume data set using one or more attributes

ABSTRACT

A method and system are disclosed for creating a combination attribute volume or combo volume by combining one or more attribute volumes into a single volume. For instance, seismic data volumes may be used for creating a combination seismic attribute volume from multiple seismic attribute volumes. This is accomplished by replacing certain of the standard 8-bit data values in a seismic data volume with marker values that denote certain values of other, spatially coincident, seismic attribute data. The resulting combo volume may then be displayed and a seed pick positioned on an event of interest such as a geological body. An auto-picker function or program will then find all the connecting points which will quickly further define the event. The event may then be displayed and interpreted.

This application claims the benefit of PCT application Ser. No.PCT/US01/03227 filed on Jan. 31, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to imaging of three-dimensional(“3D”) volume data sets. More particularly, the present inventionrelates to improved imaging and analysis of physical attributesrepresenting events within 3D volume data sets.

2. Related Art

Many fields of endeavor require the analysis and imaging of 3D volumedata sets. For example, in the medical field, a computerized axialtomography (“CAT”) scanner or a magnetic resonance imaging (“MRI”)device is used to produce a picture or diagnostic image of some part ofa patient's body. The scanner or MRI device generates a 3D volume dataset that needs to be imaged or displayed so that medical personnel cananalyze the image and form a diagnosis.

Three-dimensional volume data sets are also used in various fields ofendeavor relating to the earth sciences. Seismic sounding is one methodfor exploring the subsurface geology of the earth. An undergroundexplosion or earthquake excites seismic waves, similar to low frequencysound waves, that travel below the surface of earth and are detected byseismographs. The seismographs record the time of arrival of the seismicwaves, both direct and reflected waves. Knowing the time and place ofthe explosion or earthquake, the time of travel of the waves through theinterior can be calculated and used to measure the velocity of the wavesin the interior. A similar technique can be used for offshore oil andgas exploration. In offshore exploration, a ship tows a sound source andunderwater hydrophones. Low frequency (e.g. 50 Hz) sound waves aregenerated by, for example, a pneumatic device that works like a balloonburst. The sounds bounce off rock layers below the sea floor and arepicked up by the hydrophones. In this manner, subsurface sedimentarystructures that trap oil, such as faults, folds, and domes, are “mapped”by the reflected waves. The data is processed to produce 3D volume datasets that include a reflection or seismic amplitude datavalue atspecified (x, y, z) locations within a geographic space.

A 3D volume data set is made up of “voxels” or volume elements having x,y, z coordinates. Each voxel has a numeric data value for some measuredor calculated physical property, at a given location. A data value may,for instance, be an eight bit data word which may include 256 possiblevalues. Examples of geological data values include amplitude, phase,frequency, and semblance. Different data values are stored in different3D volume data sets, wherein each 3D volume data set represents adifferent data value. In order to analyze certain geological structuresreferred to as “events”, information from different 3D volume data setsmust be interpreted and then used to analyze different events.

One conventional method of displaying multiple 3D volume data setsrequires that the voxels be resealed in order that the data values fromeach 3D volume data set fit within the 256 data value range for colordisplay which causes a reduction in accuracy of each 3D volume data set.Another conventional method displays each 3D volume data set, however,controls the visual display of each 3D volume data set by adjustingtransparency.

In an article written by Jack Lees, in March 1999, published in TheLeading Edge, entitled “Constructing Faults from Seed Picks by VoxelTracking,” two 3D volume data sets, each using only 128 data values of a256-data value range, are combined in a single display. The displayresolution was significantly reduced, thereby limiting the ability toaccurately interpret certain events.

Consequently, there is a need in the art for a system and method tovisualize one or more 3D volume data sets with improved accuracy andresolution. Those skilled in the art have therefore long sought and willgreatly appreciate the present invention which addresses these and otherproblems. For purposes of describing the present invention, the terms“image” and “visualize” may be interchangeably used.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide animproved system and method for visualizing and interpreting multiple 3Dvolume data sets in a single combined 3D volume data set.

It is another object of the present invention to provide an improvedsystem and method for visualizing and interpreting a single 3D volumedata set in a single enhanced 3D volume data set.

It is still another object of the present invention to provide animproved system and method for visualizing and interpreting one or more3D volume data sets using a base 3D volume data set scaled across 256points, wherein select data values from the one or more 3D volume datasets may be inserted into the base 3D volume data set without changingthe scaling of the base 3D volume data set.

An advantage of the present invention is improved resolution of selectedevents.

Another advantage of the present invention is the ability to accuratelyand efficiently display selected data values related to an event frommore than two 3D volume data sets.

Yet another advantage of the present invention is the ability to displaydata values from multiple 3D volume data sets at the same time.

Yet another advantage of the present invention is greater accuracy thantransparency displays.

Yet another advantage of the present invention is the ability to focuson key events in lower quality data value ranges.

Yet another advantage of the present invention is the reduction ininterpretation cycle time.

These and other objects, features, and advantages of the presentinvention will become apparent from the drawings, the descriptions givenherein, and the appended claims.

Therefore, the present invention provides a system and method forimaging one or more 3D volume data sets for purposes of more accuratelyand efficiently analyzing and interpreting different selected events.Each 3D volume data set comprises a plurality of voxels wherein eachvoxel comprises a data value positioned at a 3D location in a respective3D volume data set. One preferred embodiment includes a method ofcombining multiple 3D volume data sets by selecting a first 3D volumedata set representing a first attribute, selecting a second 3D volumedata set representing a second attribute, and rendering an output 3Dvolume data set by comparing each of the data values in at least one ofthe first 3D volume data set and the second 3D volume data set with apreselected data value range or criteria. For each data value where thecriteria are met, the method further comprises inserting a firstselected data value at a position corresponding with the respective datavalue in the output 3D volume data set. For each data value where thecriteria are not met, the method further comprises inserting a secondselected data value at a position corresponding with the respective datavalue in the output 3D volume data set. The method may further comprisedisplaying at least one section of the output 3D volume data set andselecting a data value by inserting a seed pick in the display forvisualizing and interpreting an event.

The first selected data value may be related to the first attribute andthe second selected data value may be related to the second attribute.The seed pick is visually positioned at a selected data value using thedisplay of the output 3D volume data set. A computer and softwareprogram are preferably used for identifying or “auto-picking” all datavalues connected to the seed pick having the same or similar data valueas the respective seed pick. Thus, the present invention may comprise aprogram storage device readable by a machine, embodying a program ofinstructions executable by the machine to ultimately image the output 3Dvolume data set.

In a preferred embodiment, the first 3D volume data set and the second3D volume data set each comprise seismic data. The method also permitsadditional 3D volume data sets to be combined and therefore, may includeproducing a third 3D volume data set representing a third attribute, andcomparing each of the data values therein against a second preselecteddata value range.

In another embodiment of the present invention, an enhanced 3D volumedata set related to one of a plurality of attributes may be used tovisualize and interpret different selected events. In this embodiment,the method includes identifying each data value from a 3D volume dataset which represents a particular attribute. An enhanced 3D volume dataset is then created by selecting a data value range or criteria andcomparing each data value with the criteria. If the criteria are met,then the method further comprises inserting a first selected data valueat a position corresponding with the respective data value in theenhanced 3D volume data set. If the criteria are not met, then themethod comprises leaving the data value unchanged in the enhanced 3Dvolume data set. Additional steps may include displaying at least asection of the enhanced 3D volume data set, selecting a data value byinserting a seed pick in the display, and auto-picking a plurality ofdata values connected to the seed pick which have a data value identicalto that of the seed pick.

In another embodiment of the present invention, a method is provided forcreating a combined 3D volume data set derived from multiple 3D volumedata sets. The method comprises selecting a base 3D volume data setwherein the base 3D volume data set may comprise data values having a 3Dcoordinate and a base dataword. The base dataword may preferably berelated to a first attribute. Additionally, the method comprisesselecting a second three-dimensional volume data set where the second 3Dvolume data set may comprise data values having a spatially coincidentcoordinate with respect to the base 3D volume data set and a seconddataword related to a second attribute. The method further comprisesrendering a combined 3D volume data set by selecting data values in thesecond 3D volume data set based on a preselected data value range orcriteria. If the criteria are met, then the method further comprisesreplacing the base dataword at a respective coordinate in the base 3Dvolume data set with a selected data value related to the secondattribute. If the criteria are not met, then the method comprisesleaving the base dataword related to the first attribute at therespective coordinate in the base 3D volume data set unchanged. Aftercreating the combined 3D volume data set, the method may furthercomprise displaying at least a portion of the combined 3D volume dataset and positioning a seed pick on an event using the display. In oneembodiment of the invention, the event is a geological structure.

Continuing in this manner, additional method steps may include selectinga third 3D volume data set where the third 3D volume data set mayinclude data values having a spatially coincident coordinate withrespect to the base 3D volume data set and a third dataword related to athird attribute. The method then comprises rendering a revised combined3D volume data set by selecting data values in the third 3D volume dataset based on a second preselected data value range or criteria. If thesecond criteria are met, then the method further comprises replacing thebase dataword at the respective coordinate in the base 3D volume dataset with a second selected data value related to the third attribute. Ifthe second criteria are not met, then the method further comprisesleaving the base dataword related to the first attribute at therespective coordinate in the base 3D volume data set unchanged. In apreferred embodiment, the first attribute, the second attribute, and thethird attribute are each related to seismic data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram illustrating one embodiment for implementingthe present invention;

FIG. 2 is a schematic view illustrating the relationship between atypical seismic trace and a data value or voxel;

FIG. 3 is a schematic view illustrating an example of seismic amplitudedata values given a range between −128 and 127 (an eight bit data value)with an associated data value histogram;

FIG. 4 is a schematic view illustrating the relationship between a peak(a positive phase) event and corresponding data values;

FIG. 5 is a schematic view illustrating seed picks for auto picking allconnected points within a defined data value range;

FIG. 6 is a schematic view illustrating a resulting geobody outlined bythe auto-pick process; and

FIG. 7 illustrates one embodiment of a software program or systemarchitecture for implementing the present invention.

While the present invention will be described in connection withpresently preferred embodiments, it will be understood that it is notintended to limit the invention to those embodiments. On the contrary,it is intended to cover all alternatives, modifications, and equivalentsincluded within the spirit of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Overview

Combination volumes (“Combo Volumes”) are created by combining one ormore attributes into a single combined attribute volume or Combo Volume.In one example related to seismic attributes within a 3D volume dataset, this is accomplished by replacing certain data values (typicallyhaving 256 possible values in a seismic attribute 3D volume data set)with another data value (such as an 8-bit seismic marker data value)that denotes certain values of other spatially coincident seismicattribute data values. Combo Volumes are especially useful for enhancingthe performance of voxel-based autotrackers. Examples highlighting theutility of Combo Volumes for use in interpreting seismic data includeseismic amplitude/instantaneous phase Combo Volumes for auto-trackinglow amplitude discontinuous events. By events it is meant geobodies,such as geological structures depicted by the seismic data. In anotherexample, seismic amplitude/semblance Combo Volumes may be used forstopping the autotracker at geologic discontinuities such as faults orother geologic boundaries. In yet another example, seismicamplitude/instantaneous frequency Combo Volumes may be used forhighlighting particular geologic features as expressed seismically, suchas onlap onto a peak event or onlap onto a trough event. Commercial usesfor oil and gas exploration and development may include event mapping,model building, multi-attribute displays, and auto-picking enhancement.

SYSTEM DESCRIPTION

Referring now to FIG. 1, a method 10 in accord with the presentinvention is illustrated for determining the data values associated withvoxels for creating an output volume data set. As known by those ofskill in the art, a voxel comprises a 3D coordinate location and a datavalue, such as a 256-value data word, i.e. an 8-bit word. In step 12,the data values VS, V1, . . . , VN for each spatially coincident volumeat the same coordinate or point P are determined where VS may be thedata value of an original seismic volume at a point P, V1 may be thedata value of attribute volume 1 (VOL 1) at point P, and so forth suchthat VN is the data value of attribute volume N (VOL N) at point P. Thedata value of the Combo Volume (VC) at point P is then determined asgenerally illustrated in steps 14, 16 and 18.

In step 14, it is determined whether VS, V1, . . . , VN lie withinuser-specified criteria; for instance, whether these data values arewithin a user-specified range of data values which may be selected foreach of VOL S, VOL 1, . . . , VOL N. As illustrated in step 16, if VS,V1, . . . , VN do not lie within the criteria, then the data value of VCis set; for instance, to the same data value as VS at point P. Otheruser-specified data values can be used, or data values taken from any ofthe 3D volume data sets at the respective point P could be used. Asshown in step 18, if VS, V1, . . . , VN lie within the criteria, thenthe data value of VC is set at a user-specified marker data value thatis related to one of the attribute volumes VS, V1, . . . , VN. Asindicated in step 20, the criteria are then applied to each point P,i.e., each voxel for the Combo Volume to be produced. Once thisreiterative process is complete, a section, slice or other view of theCombo Volume may be displayed as indicated by step 22. A seed pick maythen be chosen from a visually discernable event and the voxelsconnected thereto having the same data value as the seed pick will beautomatically identified as indicated by the “auto-pick” process in step24. This method quickly and accurately defines the extent of an eventsuch as a geological structure. The extent of the event could then bedisplayed for analysis and interpretation.

One embodiment of a Combo Volume used for enhancing the ability toautotrack or auto-pick sub-surface salt boundaries utilizes three 3Dvolume data sets, each representing a different attribute such asinstantaneous frequency, seismic amplitude and instantaneous amplitude.This embodiment of a Combo Volume used to detect and display saltboundaries may be configured using conventional methods to determine theinstantaneous amplitude attribute (IA) of the seismic amplitude data(SA) and the instantaneous frequency of the instantaneous amplitudeattribute (IFIA). Accordingly, a new salt detection (SD) Combo Volumemay be configured as follows:

If f1≦IFIA(x, y, z)≦f2 AND a1≦SA(x, y, z)≦a2,

THEN SD(x, y, z)=v1,

ELSE SD(x, y, z)=IA(x, y, z).

The values of f1, f2, a1, a2, and v1 are user selected.

Another embodiment of a Combo Volume consisting of seismic amplitudedata and instantaneous phase data can be constructed to enhance theability to autotrack another seismic event. The instantaneous phase datais derived from the seismic amplitude data using conventional methods.The result is a 3D volume data set having instantaneous phase datavalues corresponding to each seismic amplitude data value or voxel. Ateach and every voxel, the instantaneous phase data value is compared toa user-specified data value or criteria. If the instantaneous phase datavalue satisfies the criteria, then that data value is replaced in thenew Combo Volume with a user-specified marker data value. If theinstantaneous phase data value does not satisfy the criteria, then thatdata value in the new Combo Volume is replaced with the correspondingsample data value from the 3D volume data set representing seismicamplitude.

More than two 3D volume data sets can be used, and constraints set foreach one, considering spatially coincident data volumes A(x, y, z), B(x,y, z), and C(x, y, z), wherein data volume D(x, y, z) is configured asfollows:

IF a1≦A(x, y, z)≦a2 AND/OR b1≦B(x, y, z)≦b2 AND/or c1≦C(x, y, z)≦c2,

THEN D(x, y, z)=some specific user selected data value,

ELSE D(x, y, z)=another value.

Referring now to FIG. 2, the relationship between a typical seismictrace 26 and a plurality of voxels 28 is shown. A sample data value rate30 is measured at a predetermined interval along seismic trace 26. Thevoxels 28 are a 3D representation or box around samples 25 of seismictrace 26. For seismic data purposes, the voxel may typically have 256possible data values which may be labeled 0 to 255 or −128 to 127, or adata value range determined by the type of data being used. The measureddata values for any 3D volume data set are divided between voxels 28.

FIG. 3 illustrates an example of seismic amplitude data values given therange −128 to 127 with an associated data histogram.

FIG. 4 illustrates the relationship between a peak (positive phase)event 27 and the associated voxels 29.

Another embodiment of the present invention involves creation of anenhanced 3D volume data set. The enhanced 3D volume data set is used toenhance the ability of the autotracker to create surfaces, events an/orgeobodies. While this method can be applied to any type of 3D volumedata set, seismic phase data values are used in reference to thefollowing description. The enhanced 3D volume data set combines certainof the 256 data values in an 8-bit seismic data volume with markervalues that are associated with such certain data values.

In order to create an enhanced 3D volume data set representing seismicphase, a range of data values is selected around the maximum peak phasedata value. For instance, when using a peak data value scale from 0 to255, where a peak would be a data value of 127, a potential range mightbe from about 115 to 139. All voxels in the 3D volume data set would betested and any voxels having a data value in this range may be redefinedwith a user-selected data value such as 127. As illustrated in FIG. 5, aseed pick 32 pick may then be visually positioned within a selectedevent. A computer generated process may then identify or auto-pick, anddisplay any point 38 connected to the seed pick 32 within a rangedefined by an upper boundary 34 and a lower boundary 36 that wouldeither include or exclude that data value as more particularlyillustrated in FIG. 5 which outlines a geobody formed as a result of theseed pick and auto-pick processes applied to an enhanced seismic phase3D volume data set.

In another embodiment, a Combo Volume is derived from more than one 3Dvolume data set. It is important to note that the method of the presentinvention can be applied using any combination of 3D volume data sets,but for explanation purposes a seismic example is provided using acombination of seismic attribute, seismic phase and seismic amplitudedata volumes. A base 3D volume data set is selected. The base 3D volumedata set will retain its histogram distribution across the amplituderange (−128 to 127) as shown for example in FIG. 3. On a scale of 0 to255, 0 would be a −128 trough and 255 would be a 127 peak. A second 3Dvolume data set is selected from which to choose key voxels to combinewith the base 3D volume data set.

In this embodiment, seismic phase data is used in reference to thefollowing description. A range of data values is selected around themaximum peak seismic phase data value. When using a peak data valuescale from 0 to 255, where a peak would be a data value of 127, apotential range might be from about 115 to 139. All voxels within thisrange would be redefined with a data value of 127 (maximum peak) or 255on a scale 0 to 255. The resulting Combo Volume would be displayed and aseed pick would then be positioned on the key event. The auto-pickerprocess would then find all the connected points as described inreference to FIG. 5.

The present invention may be implemented using hardware, software or acombination thereof, and may be implemented in a computer system orother processing system. One embodiment of a software or programstructure 100 for implementing the present invention is shown in FIG. 7.At the base of program structure 100 is an operating system 102.Suitable operating systems 102 include, for example, the UNIX® operatingsystem, or Windows NT® from Microsoft Corporation, or other operatingsystems as would be apparent to one of skill in the relevant art.

Menu and windowing software 104 overlays operating system 102. Menu andwindowing software 104 are used to provide various menus and windows tofacilitate interaction with the user, and to obtain user input andinstructions. Menu and windowing software 104 can include, for example,Microsoft Windows™, X Window System™ (registered trademark ofMassachusetts Institute of Technology), and MOTIF™ (registered trademarkof Open Software Foundation Inc.). As would be readily apparent to oneof skill in the relevant art, other menu and windowing software couldalso be used.

A basic graphics library 106 overlays menu and windowing software 104.Basic graphics library 106 is an application programming interface (API)for 3D computer graphics. The functions performed by basic graphicslibrary 106 include, for example, geometric and raster primitives, RGBAor color index mode, display list or immediate mode, viewing andmodeling transformations, lighting and shading, hidden surface removal,alpha blending (translucency), anti-aliasing, texture mapping,atmospheric effects (fog, smoke, haze), feedback and selection, stencilplanes, and accumulation buffer.

A particularly preferred basic graphics library 106 is OpenGL®,available from Silicon Graphics, Inc. (“SGI”), Mountain View, Calif. TheOpenGL® API is a multi-platform industry standard that is hardware,window, and operating system independent. OpenGL® is designed to becallable from C, C++, FORTRAN, Ada and Java programming languages.OpenGL® performs each of the functions listed above for basic graphicslibrary 106 Some commands in OpenGL® specify geometric objects to bedrawn, and others control how the objects are handled. All elements ofthe OpenGL® state, even the contents of the texture memory and the framebuffer, can be obtained by a client application using OpenGL®. OpenGL®and the client application may operate on the same or different machinesbecause OpenGL® is network transparent. OpenGL® is described in moredetail in the OpenGL® Programming Guide (ISBN: 0-201-63274-8) and theOpenGL® Reference Manual (ISBN: 0-201-63276-4), the entirety of both ofwhich are incorporated herein by reference.

Visual simulation graphics library 108 overlays basic graphics library106. Visual simulation graphics library 108 is an API for creatingreal-time, multi-processed 3D visual simulation graphics applications.Visual simulation graphics library 108 provides functions that bundletogether graphics library state control functions such as lighting,materials, texture, and transparency. These functions track state andthe creation of display lists that can be rendered later.

A particularly preferred visual simulation graphics library 108 is IRISPerformer, available from SGI in Mountain View, Calif. IRIS Performersupports the OpenGL® graphics library discussed above. IRIS Performerincludes two main libraries, libpf and libpr, and four associatedlibraries, libpfdu, libpfdb, libpfui, and libpfutil.

The basis of IRIS Performer is the performance rendering library libpr,a low-level library providing high speed rendering functions based onGeoSets and graphics state control using GeoStates. GeoSets arecollections of drawable geometry that group same-type graphicsprimitives (e.g., triangles or quads) into one data object. The GeoSetcontains no geometry itself, only pointers to data arrays and indexarrays. Because all the primitives in a GeoSet are of the same type andhave the same attributes, rendering of most databases is performed atmaximum hardware speed. GeoStates provide graphics state definitions(e.g., texture or material) for GeoSets.

Layered above libpr is libpf, a real-time visual simulation environmentproviding a high-performance multi-process database rendering systemthat optimizes use of multiprocessing hardware. The database utilitylibrary, libpfdu, provides functions for defining both geometric andappearance attributes of 3D objects, shares state and materials, andgenerates triangle strips from independent polygonal input. The databaselibrary libpfdb uses the facilities of libpfdu, libpf, and libpr toimport database files in a number of industry standard database formats.The libpfui is a user interface library that provides building blocksfor writing manipulation components for user interfaces (C and C++programming languages). Finally, the libpfutil is the utility librarythat provides routines for implementing tasks such as MultiChannelOption support and graphical user interface (GUI) tools.

An application program which uses IRIS Performer and OpenGL® APItypically carry out the following steps in preparing for real-time 3Dvisual simulation:

1. Initialize IRIS Performer;

2. Specify number of graphics pipelines, choose the multiprocessingconfiguration, and specify hardware mode as needed;

3. Initialize chosen multiprocessing mode;

4. Initialize frame rate and set frame-extend policy;

5. Create, configure, and open windows as required; and

6. Create and configure display channels as required.

Once the application program has created a graphical renderingenvironment by carrying out steps 1 through 6 above, then theapplication program typically iterates through a main simulation looponce per frame.

7. Compute dynamics, update model matrices, etc.;

8. Delay until the next frame time;

9. Perform latency critical viewpoint updates; and

10. Draw a frame.

A combo/enhanced volume program 110 of the present inventions overlaysvisual simulation graphics library 108. Program 110 interacts with, anduses the functions carried out by, each of visual simulation andgraphics library 108, basic graphics library 106, menu and windowingsoftware 104, and operating system 102 in a manner known to one of skillin the relevant art.

Program 110 of the present invention is preferably written in an objectoriented programming language to allow the creation and use of objectsand object functionality. A particularly preferred object orientedprogramming language is C++.

In one embodiment, program 110 stores the 3D volume data set in a mannerwell known to one of skill in the relevant art. For example, the formatfor data volume can consist of two parts, a volume header followed bythe body of data that is as long as the size of the data set. The volumeheader typically contains information, in a prescribed sequence, such asthe file path (location) of the data set, size, dimensions in the x, y,and z directions, annotations for the x, y, and z axes, annotations forthe datavalue, etc. The body of data is a binary sequence of bytes, oneor more bytes per data value, that can be ordered in the followingmanner. The first byte is the datavalue at volume location (x, y,z)=(0,0,0). The second byte is the datavalue at volume location (1,0,0),the third byte is the datavalue at volume location (2,0,0), etc. Whenthe x dimension is exhausted, then the y dimension is incremented, andfinally the z dimension is incremented. The present invention is notlimited in any way to a particular data format.

The program 110 facilitates input from a user to identify one or 3Dvolume data sets to use for imaging and analysis. When a plurality ofdata volumes is used, the datavalue for each of the plurality of datavolumes represents a different physical parameter or attribute for thesame geographic space. By way of example, a plurality of data volumescould include a geology volume, a temperature volume, and awater-saturation volume. The voxels in the geology volume can beexpressed in the form (x, y, z, seismic amplitude). The voxels in thetemperature volume can be expressed in the form (x, y, z, ° C.). Thevoxels in the water-saturation volume can be expressed in the form (x,y, z, % saturation). The physical or geographic space defined by thevoxels in each of these volumes is the same. However, for any specificspatial location (x₀, y₀, z₀), the seismic amplitude would be containedin the geology volume, the temperature in the temperature volume, andthe water-saturation in the water-saturation volume.

Conclusion

The foregoing disclosure and description of the invention isillustrative and explanatory thereof, and it will be appreciated bythose skilled in the art, that various changes in the size, shape andmaterials, the use of mechanical equivalents, as well as in the detailsof the illustrated construction or combinations of features of thevarious elements may be made without departing from the spirit of theinvention.

What is claimed is:
 1. A method for combining a plurality of 3D volumedata sets in a single output 3D volume data set, each 3D volume data setcomprising a plurality of voxels, each voxel comprising a data value andbeing positioned at a 3D location in a respective 3D volume data set,said method comprising: selecting a first 3D volume data setrepresenting a first attribute; selecting a second 3D volume data setrepresenting a second attribute; comparing each of said data values inat least one of said first 3D volume data set and said second 3D volumedata set with a preselected data value range; inserting a first selecteddata value at a position corresponding with said respective data valuein said output 3D volume data set for each data value within said datavalue range; inserting a second selected data value at a positioncorresponding with said respective data value in said output 3D volumedata set for each data value outside said data value range; anddisplaying at least one section of said output 3D volume data set. 2.The method of claim 1, wherein said first selected data value is relatedto said first attribute.
 3. The method of claim 1, wherein said secondselected data value is related to said second attribute.
 4. The methodof claim 1, further comprising: inserting a seed pick in said displayfor determining an event related to a physical phenomena, said seed pickbeing positioned at a respective data value position using said display.5. The method of claim 4, further comprising: auto-picking all datavalues connected to said seed pick which have the same data value assaid respective data value at which said seed pick is positioned.
 6. Themethod of claim 4, wherein said first 3D volume data set and said second3D volume data set are comprised of seismic data and said event is ageological structure.
 7. The method of claim 1, further comprising:selecting a third 3D volume data set representing a third attribute;comparing each of said data values in at least one of said first 3Dvolume data set, said second 3D volume data set, and said third 3Dvolume data set with said preselected data value range; inserting saidfirst selected data value at a position corresponding with saidrespective data value in said output 3D volume data set for each datavalue within said data value range; inserting said second selected datavalue at a position corresponding with said respective data value insaid output 3D volume data set for each data value outside said datavalue range; and displaying at least one section of said output 3Dvolume data set.
 8. A program storage device readable by a machineembodying a program of instructions executable by the machine to performmethod steps of imaging an output 3D volume data set, the 3D volume dataset including a plurality of voxels, each voxel defined by a 3Dcoordinate and a data value, the method comprising: selecting aplurality of spatially coincident 3D volume data sets wherein each ofsaid 3D volume data sets is related to at least one of a correspondingplurality of attributes; selecting one or more selectable criteria forcomparing with data values of one or more of said plurality of spatiallycoincident data sets; inserting a first preselected data value at acoordinate corresponding with said respective data value in said output3D volume data set when said data value meets said one or moreselectable criteria; and displaying at least one section of said output3D volume data set.
 9. The program storage device of claim 8, whereinsaid first preselected data value is related to at least one of saidplurality of attributes.
 10. The program storage device of claim 9,further comprising: inserting a second preselected data value at acoordinate corresponding with said respective data value in said output3D volume data set when said data value meets said one or moreselectable criteria.
 11. The program storage device of claim 10, whereinsaid second preselected data value is relaxed to at least another one ofsaid plurality of attributes.
 12. The program storage device of claim 8,wherein said plurality of attributes is each related to seismic data.13. A method for displaying an enhanced 3D volume data set related toone of a plurality of attributes using a 3D volume data set comprising aplurality of voxels, each voxel comprising a data value and beingpositioned at a 3D location in said 3D volume data set, said methodcomprising: selecting each data value within a data value range, saiddata value range being related to one of said plurality of attributes;selecting a comparing each selected data value with said criteria;inserting a preselected data value at a position corresponding with saiddata value in said enhanced 3D volume data set when said darn valuemeets said criteria; inserting said data value at a positioncorresponding with said respective data value in said enhanced 3D volumedata set when said data value does not meet said criteria; displaying atleast a section of said enhanced 3D volume data set; utilizing saiddisplay for inserting a seed pick at a selected event shown in saiddisplay; and auto-picking a plurality of data values connected to saidseed pick which have a data value identical to said seed pick data valueat which said seed pick is positioned for automatically determining anextent of said event.
 14. A method for rendering a combo volume derivedfrom a plurality of 3D volume data sets, comprising: selecting a base 3Dvolume data set, said base 3D volume data set comprising voxels having a3D coordinate and a base dataword, said base dataword being related to afirst attribute; selecting a second 3D volume data set, said second 3Dvolume data set comprising voxels having a spatially coincidentcoordinate with respect to said base 3D volume data set and a seconddataword related to a second attribute; selecting voxels in said second3D volume data set based on a first preselected data value range;rendering said combo volume by replacing said base dataword in said base3D volume data set with a first preselected data value related to saidsecond attribute when said respective voxel in said second 3D volumedata set is within said first preselected data value range; anddisplaying at least a portion of said combo volume.
 15. The method ofclaim 14, further comprising: positioning a seed pick on an event usingsaid display, and identifying points connected to said seed pick whichhave the same dataword as said seed pick.
 16. The method of claim 15,wherein said event is a geological structure.
 17. The method of claim14, further comprising: selecting a third 3D volume data set, said third3D volume data set comprising voxels having a spatially coincidentcoordinate with respect to said base 3D volume data set and a thirddataword related to a third attribute; selecting voxels in said third 3Dvolume data set based on a second preselected data value range;rendering a revised combo volume by replacing said base dataword in saidbase 3D volume data set with a second preselected data value related tosaid third attribute when said respective voxel in said third 3D volumedata set is within said second preselected data value range; anddisplaying at least a portion of said revised combo volume.
 18. Themethod of claim 17, wherein said first attribute, said second attribute,and said third attribute are each related to seismic data.